In this chapter, we discussed the different problems
TCP/IP troubleshooting commands like ping, traceroute, and show ip route are used to isolate problems in EIGRP environments.
EIGRP packets are
The show ip eigrp interfaces command shows a list of interfaces in which EIGRP is enabled.
The show ip eigrp neighbors command shows EIGRP enabled routers that are on directly connected networks of a router.
The show ip eigrp topology command shows topology of an entire EIGRP domain.
The show ip eigrp traffic command shows statistics of the EIGRP generated traffic.
The debug eigrp neighbors command
The debug eigrp packets command monitors EIGRP packets.
The debug eigrp transmit command tracks all EIGRP transmission events, such as ack, packetize, startup, peerdown, link, build,
The debug eigrp fsm command displays EIGRP DUAL algorithm functioning and stages of building topology table.
Misconfiguration occurs because networks are not declared or because the same AS is not defined in all routers in the EIGRP domain.
EIGRP neighbor problems occur when a new node is added or when initially existing neighbor relations are no longer present in the network.
Routers that fail to reply to queries are said to be in Stuck-In-Active (SIA) state.
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Open Shortest Path First (OSPF) is an industry standard protocol that ensures interoperability between routing devices manufactured by diverse
This chapter discusses different
This section discusses the terminology used when discussing the OSPF routing protocol. Some of the terms are:
Link State Advertisement (LSA): OSPF packet containing source, destination, and routing information. This information is advertised to all OSPF routers in a hierarchical area.
Flooding: Periodic updating of topology and routing table information with sending of LSAs.
Adjacencies: Logical connection between OSPF router and its Designated Router (DR).
Designated Router:
Router used to reduce the number of adjacencies
Backup Designated Router (BDR): Router that acts as a standby for DR on broadcast networks. BDR collects routing information updated from the adjacent OSPF routers and takes the role of DR when the DR goes down.
Autonomous Systems (ASs): Set of routers in the same administrative control using the same protocol for routing processes.
Multi-access/Broadcast Networks: Physical networks that support interconnection of more than two routers that can communicate directly.
Nonbroadcast Multi-access Networks (NBMAs): Interconnect routers in an OSPF network without having the broadcast capability. NBMA is discussed in detail in a later section.
Single Area (SA): Logical subdivision of the greater OSPF domain, grouping routers that run OSPF with identical topological databases.
Stub Area: Type of nonstandard OSPF area.
Totally Stubby Area (TSA): Type of nonstandard OSPF area used when few networks with limited connectivity are connected to the remaining network.
Not So Stubby Area (NSSA): Type of nonstandard OSPF area used in redistribution of routing information.
OSPF Routers: Four types of OSPF routers are Internal Router (IR), Area Border Router (ABR), Backbone Router (BR), and Autonomous System Boundary Router (ASBR).